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B-body disc brake swap #1750271 02/09/15 08:36 PM 02/09/15 08:36 PM
Joined: Jun 2013 Posts: 870 Keizer, Oregon U.S.A. E elmor353 OP super stock
elmor353 OP super stock E Joined: Jun 2013 Posts: 870 Keizer, Oregon U.S.A.	Just finishing up a disc brake swap on a 65 Coronet. I used mid-70's A-body spindles, rotors, calipers, proportioning valve and a 75 A-body manual disc master cylinder. When the pedal is out against the stop and the master pushrod is all the way out, the pushrod mounting hole seems to line up with the pedal arm just fine. However, I only have 2.5 to 3 inches travel before the master cylinder bottoms out. The pedal stops about 4 inches or so from the floor. Is this normal for this swap or am I missing something?

Re: B-body disc brake swap [Re: elmor353] #1750272 02/09/15 09:12 PM 02/09/15 09:12 PM
Joined: Jan 2003 Posts: 28,068 Irving, TX feets Senior Management
feets Senior Management Joined: Jan 2003 Posts: 28,068 Irving, TX	You're positive that the master cylinder is bottoming out? What is the distance from the brake pedal pivot to the master cylinder push rod? We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon

Re: B-body disc brake swap [Re: elmor353] #1750273 02/10/15 05:09 PM 02/10/15 05:09 PM
Joined: Jan 2003 Posts: 25,916 Rio Linda, CA John_Kunkel Too Many Posts
John_Kunkel Too Many Posts Joined: Jan 2003 Posts: 25,916 Rio Linda, CA	Was the '65 Coronet originally manual brake or power brake? (thinking incorrect pedal ratio) The INTERNET, the MISinformation superhighway

Re: B-body disc brake swap [Re: John_Kunkel] #1750274 02/10/15 06:03 PM 02/10/15 06:03 PM
Joined: Jun 2013 Posts: 870 Keizer, Oregon U.S.A. E elmor353 OP super stock
elmor353 OP super stock E Joined: Jun 2013 Posts: 870 Keizer, Oregon U.S.A.	The Coronet was originally manual brakes. I have not measured from the pedal pivot to the push rod. I will measure it tonight.

Re: B-body disc brake swap [Re: elmor353] #1750275 02/10/15 06:05 PM 02/10/15 06:05 PM
Joined: Jan 2003 Posts: 31,060 Oregon A AndyF I Win
AndyF I Win A Joined: Jan 2003 Posts: 31,060 Oregon	How did you mount the master cylinder to the firewall? If you used an adapter then your spacing might be different. You might need an adjustable pushrod for the master cylinder.

Re: B-body disc brake swap [Re: elmor353] #1750276 02/10/15 08:01 PM 02/10/15 08:01 PM
Joined: Jan 2003 Posts: 28,068 Irving, TX feets Senior Management
feets Senior Management Joined: Jan 2003 Posts: 28,068 Irving, TX	Do you have any free movement in the pedal or is it always putting pressure on the master cylinder? We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon

Re: B-body disc brake swap [Re: feets] #1750277 02/10/15 08:49 PM 02/10/15 08:49 PM
Joined: Jun 2013 Posts: 870 Keizer, Oregon U.S.A. E elmor353 OP super stock
elmor353 OP super stock E Joined: Jun 2013 Posts: 870 Keizer, Oregon U.S.A.	I mounted the master directly to the firewall just like the original unit. It seems that the push rod has the plunger about 3/16th's into the bore, so there is a little pressure at all times.

Re: B-body disc brake swap [Re: elmor353] #1750278 02/10/15 09:40 PM 02/10/15 09:40 PM
Joined: Jan 2003 Posts: 28,068 Irving, TX feets Senior Management
feets Senior Management Joined: Jan 2003 Posts: 28,068 Irving, TX	Then you are likely bottoming the MC. You should have an inch or so of free pedal movement. Your choices are to either space the MC away from the firewall or get a shorter/adjustable push rod. We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon

Re: B-body disc brake swap [Re: elmor353] #1750279 02/11/15 12:13 AM 02/11/15 12:13 AM
Joined: Jan 2003 Posts: 31,060 Oregon A AndyF I Win
AndyF I Win A Joined: Jan 2003 Posts: 31,060 Oregon	The original '65 master cylinder is a bit funky when compared to the later style. I wouldn't assume that you can do a bolt and go type of swap.

Re: B-body disc brake swap [Re: AndyF] #1750280 02/11/15 01:41 AM 02/11/15 01:41 AM
Joined: Feb 2010 Posts: 18,493 Granite Bay CA Kern Dog Striving for excellence
Kern Dog Striving for excellence Joined: Feb 2010 Posts: 18,493 Granite Bay CA	The pre 1967 single reservior DeathPot master cylinders used a shorter stroke.

Re: B-body disc brake swap [Re: Kern Dog] #1750281 02/11/15 02:07 AM 02/11/15 02:07 AM
Joined: Jun 2013 Posts: 870 Keizer, Oregon U.S.A. E elmor353 OP super stock
elmor353 OP super stock E Joined: Jun 2013 Posts: 870 Keizer, Oregon U.S.A.	I was hoping for a bolt and go, but I should have known better. This thing has fought me every step. I replaced the 65 K-member with a 66 so there would be more header choices, then I had to fabricate and change the trans cross member so it would bolt up. I have done literally dozens and dozens of engine swaps, but never had a vehicle fight me like this one. Hoping to button it up and break in the new Hughes Whiplash cam in the 383 this week. Gotta get this rig done so I can work on my own stuff. I need a beer!

Re: B-body disc brake swap [Re: elmor353] #1750282 02/11/15 08:54 PM 02/11/15 08:54 PM
Joined: Jan 2003 Posts: 28,068 Irving, TX feets Senior Management
feets Senior Management Joined: Jan 2003 Posts: 28,068 Irving, TX	Quote: I was hoping for a bolt and go, but I should have known better. This thing has fought me every step. I replaced the 65 K-member with a 66 so there would be more header choices, then I had to fabricate and change the trans cross member so it would bolt up. I have done literally dozens and dozens of engine swaps, but never had a vehicle fight me like this one. Hoping to button it up and break in the new Hughes Whiplash cam in the 383 this week. Gotta get this rig done so I can work on my own stuff. I need a beer! I had the same thing and performed the same mods. It was fun trying to find room for a pair of turbos under that hood. We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon

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